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-rw-r--r--trunk/channels/vcodecs.c1253
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diff --git a/trunk/channels/vcodecs.c b/trunk/channels/vcodecs.c
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+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright 2007-2008, Sergio Fadda, Luigi Rizzo
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*
+ * Video codecs support for console_video.c
+ * $Revision$
+ */
+
+#include "asterisk.h"
+#include "console_video.h"
+#include "asterisk/frame.h"
+#include "asterisk/utils.h" /* ast_calloc() */
+
+struct video_out_desc;
+struct video_dec_desc;
+struct fbuf_t;
+
+/*
+ * Each codec is defined by a number of callbacks
+ */
+/*! \brief initialize the encoder */
+typedef int (*encoder_init_f)(AVCodecContext *v);
+
+/*! \brief actually call the encoder */
+typedef int (*encoder_encode_f)(struct video_out_desc *v);
+
+/*! \brief encapsulate the bistream in RTP frames */
+typedef struct ast_frame *(*encoder_encap_f)(struct fbuf_t *, int mtu,
+ struct ast_frame **tail);
+
+/*! \brief inizialize the decoder */
+typedef int (*decoder_init_f)(AVCodecContext *enc_ctx);
+
+/*! \brief extract the bitstream from RTP frames and store in the fbuf.
+ * return 0 if ok, 1 on error
+ */
+typedef int (*decoder_decap_f)(struct fbuf_t *b, uint8_t *data, int len);
+
+/*! \brief actually call the decoder */
+typedef int (*decoder_decode_f)(struct video_dec_desc *v, struct fbuf_t *b);
+
+struct video_codec_desc {
+ const char *name; /* format name */
+ int format; /* AST_FORMAT_* */
+ encoder_init_f enc_init;
+ encoder_encap_f enc_encap;
+ encoder_encode_f enc_run;
+ decoder_init_f dec_init;
+ decoder_decap_f dec_decap;
+ decoder_decode_f dec_run;
+};
+
+/*
+ * Descriptor for the incoming stream, with multiple buffers for the bitstream
+ * extracted from the RTP packets, RTP reassembly info, and a frame buffer
+ * for the decoded frame (buf).
+ * The descriptor is allocated as the first frame comes in.
+ *
+ * Incoming payload is stored in one of the dec_in[] buffers, which are
+ * emptied by the video thread. These buffers are organized in a circular
+ * queue, with dec_in_cur being the buffer in use by the incoming stream,
+ * and dec_in_dpy is the one being displayed. When the pointers need to
+ * be changed, we synchronize the access to them with dec_lock.
+ * When the list is full dec_in_cur = NULL (we cannot store new data),
+ * when the list is empty dec_in_dpy = NULL (we cannot display frames).
+ */
+struct video_dec_desc {
+ struct video_codec_desc *d_callbacks; /* decoder callbacks */
+ AVCodecContext *dec_ctx; /* information about the codec in the stream */
+ AVCodec *codec; /* reference to the codec */
+ AVFrame *d_frame; /* place to store the decoded frame */
+ AVCodecParserContext *parser;
+ uint16_t next_seq; /* must be 16 bit */
+ int discard; /* flag for discard status */
+#define N_DEC_IN 3 /* number of incoming buffers */
+ struct fbuf_t *dec_in_cur; /* buffer being filled in */
+ struct fbuf_t *dec_in_dpy; /* buffer to display */
+ struct fbuf_t dec_in[N_DEC_IN]; /* incoming bitstream, allocated/extended in fbuf_append() */
+ struct fbuf_t dec_out; /* decoded frame, no buffer (data is in AVFrame) */
+};
+
+#ifdef debugging_only
+
+/* some debugging code to check the bitstream:
+ * declare a bit buffer, initialize it, and fetch data from it.
+ */
+struct bitbuf {
+ const uint8_t *base;
+ int bitsize; /* total size in bits */
+ int ofs; /* next bit to read */
+};
+
+static struct bitbuf bitbuf_init(const uint8_t *base, int bitsize, int start_ofs)
+{
+ struct bitbuf a;
+ a.base = base;
+ a.bitsize = bitsize;
+ a.ofs = start_ofs;
+ return a;
+}
+
+static int bitbuf_left(struct bitbuf *b)
+{
+ return b->bitsize - b->ofs;
+}
+
+static uint32_t getbits(struct bitbuf *b, int n)
+{
+ int i, ofs;
+ const uint8_t *d;
+ uint8_t mask;
+ uint32_t retval = 0;
+ if (n> 31) {
+ ast_log(LOG_WARNING, "too many bits %d, max 32\n", n);
+ return 0;
+ }
+ if (n + b->ofs > b->bitsize) {
+ ast_log(LOG_WARNING, "bitbuf overflow %d of %d\n", n + b->ofs, b->bitsize);
+ n = b->bitsize - b->ofs;
+ }
+ ofs = 7 - b->ofs % 8; /* start from msb */
+ mask = 1 << ofs;
+ d = b->base + b->ofs / 8; /* current byte */
+ for (i=0 ; i < n; i++) {
+ retval += retval + (*d & mask ? 1 : 0); /* shift in new byte */
+ b->ofs++;
+ mask >>= 1;
+ if (mask == 0) {
+ d++;
+ mask = 0x80;
+ }
+ }
+ return retval;
+}
+
+static void check_h261(struct fbuf_t *b)
+{
+ struct bitbuf a = bitbuf_init(b->data, b->used * 8, 0);
+ uint32_t x, y;
+
+ x = getbits(&a, 20); /* PSC, 0000 0000 0000 0001 0000 */
+ if (x != 0x10) {
+ ast_log(LOG_WARNING, "bad PSC 0x%x\n", x);
+ return;
+ }
+ x = getbits(&a, 5); /* temporal reference */
+ y = getbits(&a, 6); /* ptype */
+ if (0)
+ ast_log(LOG_WARNING, "size %d TR %d PTY spl %d doc %d freeze %d %sCIF hi %d\n",
+ b->used,
+ x,
+ (y & 0x20) ? 1 : 0,
+ (y & 0x10) ? 1 : 0,
+ (y & 0x8) ? 1 : 0,
+ (y & 0x4) ? "" : "Q",
+ (y & 0x2) ? 1:0);
+ while ( (x = getbits(&a, 1)) == 1)
+ ast_log(LOG_WARNING, "PSPARE 0x%x\n", getbits(&a, 8));
+ // ast_log(LOG_WARNING, "PSPARE 0 - start GOB LAYER\n");
+ while ( (x = bitbuf_left(&a)) > 0) {
+ // ast_log(LOG_WARNING, "GBSC %d bits left\n", x);
+ x = getbits(&a, 16); /* GBSC 0000 0000 0000 0001 */
+ if (x != 0x1) {
+ ast_log(LOG_WARNING, "bad GBSC 0x%x\n", x);
+ break;
+ }
+ x = getbits(&a, 4); /* group number */
+ y = getbits(&a, 5); /* gquant */
+ if (x == 0) {
+ ast_log(LOG_WARNING, " bad GN %d\n", x);
+ break;
+ }
+ while ( (x = getbits(&a, 1)) == 1)
+ ast_log(LOG_WARNING, "GSPARE 0x%x\n", getbits(&a, 8));
+ while ( (x = bitbuf_left(&a)) > 0) { /* MB layer */
+ break;
+ }
+ }
+}
+
+void dump_buf(struct fbuf_t *b);
+void dump_buf(struct fbuf_t *b)
+{
+ int i, x, last2lines;
+ char buf[80];
+
+ last2lines = (b->used - 16) & ~0xf;
+ ast_log(LOG_WARNING, "buf size %d of %d\n", b->used, b->size);
+ for (i = 0; i < b->used; i++) {
+ x = i & 0xf;
+ if ( x == 0) { /* new line */
+ if (i != 0)
+ ast_log(LOG_WARNING, "%s\n", buf);
+ bzero(buf, sizeof(buf));
+ sprintf(buf, "%04x: ", i);
+ }
+ sprintf(buf + 6 + x*3, "%02x ", b->data[i]);
+ if (i > 31 && i < last2lines)
+ i = last2lines - 1;
+ }
+ if (buf[0])
+ ast_log(LOG_WARNING, "%s\n", buf);
+}
+#endif /* debugging_only */
+
+/*!
+ * Build an ast_frame for a given chunk of data, and link it into
+ * the queue, with possibly 'head' bytes at the beginning to
+ * fill in some fields later.
+ */
+static struct ast_frame *create_video_frame(uint8_t *start, uint8_t *end,
+ int format, int head, struct ast_frame *prev)
+{
+ int len = end-start;
+ uint8_t *data;
+ struct ast_frame *f;
+
+ data = ast_calloc(1, len+head);
+ f = ast_calloc(1, sizeof(*f));
+ if (f == NULL || data == NULL) {
+ ast_log(LOG_WARNING, "--- frame error f %p data %p len %d format %d\n",
+ f, data, len, format);
+ if (f)
+ ast_free(f);
+ if (data)
+ ast_free(data);
+ return NULL;
+ }
+ memcpy(data+head, start, len);
+ f->data = data;
+ f->mallocd = AST_MALLOCD_DATA | AST_MALLOCD_HDR;
+ //f->has_timing_info = 1;
+ //f->ts = ast_tvdiff_ms(ast_tvnow(), out->ts);
+ f->datalen = len+head;
+ f->frametype = AST_FRAME_VIDEO;
+ f->subclass = format;
+ f->samples = 0;
+ f->offset = 0;
+ f->src = "Console";
+ f->delivery.tv_sec = 0;
+ f->delivery.tv_usec = 0;
+ f->seqno = 0;
+ AST_LIST_NEXT(f, frame_list) = NULL;
+
+ if (prev)
+ AST_LIST_NEXT(prev, frame_list) = f;
+
+ return f;
+}
+
+
+/*
+ * Append a chunk of data to a buffer taking care of bit alignment
+ * Return 0 on success, != 0 on failure
+ */
+static int fbuf_append(struct fbuf_t *b, uint8_t *src, int len,
+ int sbit, int ebit)
+{
+ /*
+ * Allocate buffer. ffmpeg wants an extra FF_INPUT_BUFFER_PADDING_SIZE,
+ * and also wants 0 as a buffer terminator to prevent trouble.
+ */
+ int need = len + FF_INPUT_BUFFER_PADDING_SIZE;
+ int i;
+ uint8_t *dst, mask;
+
+ if (b->data == NULL) {
+ b->size = need;
+ b->used = 0;
+ b->ebit = 0;
+ b->data = ast_calloc(1, b->size);
+ } else if (b->used + need > b->size) {
+ b->size = b->used + need;
+ b->data = ast_realloc(b->data, b->size);
+ }
+ if (b->data == NULL) {
+ ast_log(LOG_WARNING, "alloc failure for %d, discard\n",
+ b->size);
+ return 1;
+ }
+ if (b->used == 0 && b->ebit != 0) {
+ ast_log(LOG_WARNING, "ebit not reset at start\n");
+ b->ebit = 0;
+ }
+ dst = b->data + b->used;
+ i = b->ebit + sbit; /* bits to ignore around */
+ if (i == 0) { /* easy case, just append */
+ /* do everything in the common block */
+ } else if (i == 8) { /* easy too, just handle the overlap byte */
+ mask = (1 << b->ebit) - 1;
+ /* update the last byte in the buffer */
+ dst[-1] &= ~mask; /* clear bits to ignore */
+ dst[-1] |= (*src & mask); /* append new bits */
+ src += 1; /* skip and prepare for common block */
+ len --;
+ } else { /* must shift the new block, not done yet */
+ ast_log(LOG_WARNING, "must handle shift %d %d at %d\n",
+ b->ebit, sbit, b->used);
+ return 1;
+ }
+ memcpy(dst, src, len);
+ b->used += len;
+ b->ebit = ebit;
+ b->data[b->used] = 0; /* padding */
+ return 0;
+}
+
+/*
+ * Here starts the glue code for the various supported video codecs.
+ * For each of them, we need to provide routines for initialization,
+ * calling the encoder, encapsulating the bitstream in ast_frames,
+ * extracting payload from ast_frames, and calling the decoder.
+ */
+
+/*--- h263+ support --- */
+
+/*! \brief initialization of h263p */
+static int h263p_enc_init(AVCodecContext *enc_ctx)
+{
+ /* modes supported are
+ - Unrestricted Motion Vector (annex D)
+ - Advanced Prediction (annex F)
+ - Advanced Intra Coding (annex I)
+ - Deblocking Filter (annex J)
+ - Slice Structure (annex K)
+ - Alternative Inter VLC (annex S)
+ - Modified Quantization (annex T)
+ */
+ enc_ctx->flags |=CODEC_FLAG_H263P_UMV; /* annex D */
+ enc_ctx->flags |=CODEC_FLAG_AC_PRED; /* annex f ? */
+ enc_ctx->flags |=CODEC_FLAG_H263P_SLICE_STRUCT; /* annex k */
+ enc_ctx->flags |= CODEC_FLAG_H263P_AIC; /* annex I */
+
+ return 0;
+}
+
+
+/*
+ * Create RTP/H.263 fragments to avoid IP fragmentation. We fragment on a
+ * PSC or a GBSC, but if we don't find a suitable place just break somewhere.
+ * Everything is byte-aligned.
+ */
+static struct ast_frame *h263p_encap(struct fbuf_t *b, int mtu,
+ struct ast_frame **tail)
+{
+ struct ast_frame *cur = NULL, *first = NULL;
+ uint8_t *d = b->data;
+ int len = b->used;
+ int l = len; /* size of the current fragment. If 0, must look for a psc */
+
+ for (;len > 0; len -= l, d += l) {
+ uint8_t *data;
+ struct ast_frame *f;
+ int i, h;
+
+ if (len >= 3 && d[0] == 0 && d[1] == 0 && d[2] >= 0x80) {
+ /* we are starting a new block, so look for a PSC. */
+ for (i = 3; i < len - 3; i++) {
+ if (d[i] == 0 && d[i+1] == 0 && d[i+2] >= 0x80) {
+ l = i;
+ break;
+ }
+ }
+ }
+ if (l > mtu || l > len) { /* psc not found, split */
+ l = MIN(len, mtu);
+ }
+ if (l < 1 || l > mtu) {
+ ast_log(LOG_WARNING, "--- frame error l %d\n", l);
+ break;
+ }
+
+ if (d[0] == 0 && d[1] == 0) { /* we start with a psc */
+ h = 0;
+ } else { /* no psc, create a header */
+ h = 2;
+ }
+
+ f = create_video_frame(d, d+l, AST_FORMAT_H263_PLUS, h, cur);
+ if (!f)
+ break;
+
+ data = f->data;
+ if (h == 0) { /* we start with a psc */
+ data[0] |= 0x04; // set P == 1, and we are done
+ } else { /* no psc, create a header */
+ data[0] = data[1] = 0; // P == 0
+ }
+
+ if (!cur)
+ first = f;
+ cur = f;
+ }
+
+ if (cur)
+ cur->subclass |= 1; // RTP Marker
+
+ *tail = cur; /* end of the list */
+ return first;
+}
+
+/*! \brief extract the bitstreem from the RTP payload.
+ * This is format dependent.
+ * For h263+, the format is defined in RFC 2429
+ * and basically has a fixed 2-byte header as follows:
+ * 5 bits RR reserved, shall be 0
+ * 1 bit P indicate a start/end condition,
+ * in which case the payload should be prepended
+ * by two zero-valued bytes.
+ * 1 bit V there is an additional VRC header after this header
+ * 6 bits PLEN length in bytes of extra picture header
+ * 3 bits PEBIT how many bits to be ignored in the last byte
+ *
+ * XXX the code below is not complete.
+ */
+static int h263p_decap(struct fbuf_t *b, uint8_t *data, int len)
+{
+ int PLEN;
+
+ if (len < 2) {
+ ast_log(LOG_WARNING, "invalid framesize %d\n", len);
+ return 1;
+ }
+ PLEN = ( (data[0] & 1) << 5 ) | ( (data[1] & 0xf8) >> 3);
+
+ if (PLEN > 0) {
+ data += PLEN;
+ len -= PLEN;
+ }
+ if (data[0] & 4) /* bit P */
+ data[0] = data[1] = 0;
+ else {
+ data += 2;
+ len -= 2;
+ }
+ return fbuf_append(b, data, len, 0, 0); /* ignore trail bits */
+}
+
+
+/*
+ * generic encoder, used by the various protocols supported here.
+ * We assume that the buffer is empty at the beginning.
+ */
+static int ffmpeg_encode(struct video_out_desc *v)
+{
+ struct fbuf_t *b = &v->enc_out;
+ int i;
+
+ b->used = avcodec_encode_video(v->enc_ctx, b->data, b->size, v->enc_in_frame);
+ i = avcodec_encode_video(v->enc_ctx, b->data + b->used, b->size - b->used, NULL); /* delayed frames ? */
+ if (i > 0) {
+ ast_log(LOG_WARNING, "have %d more bytes\n", i);
+ b->used += i;
+ }
+ return 0;
+}
+
+/*
+ * Generic decoder, which is used by h263p, h263 and h261 as it simply
+ * invokes ffmpeg's decoder.
+ * av_parser_parse should merge a randomly chopped up stream into
+ * proper frames. After that, if we have a valid frame, we decode it
+ * until the entire frame is processed.
+ */
+static int ffmpeg_decode(struct video_dec_desc *v, struct fbuf_t *b)
+{
+ uint8_t *src = b->data;
+ int srclen = b->used;
+ int full_frame = 0;
+
+ if (srclen == 0) /* no data */
+ return 0;
+ while (srclen) {
+ uint8_t *data;
+ int datalen, ret;
+ int len = av_parser_parse(v->parser, v->dec_ctx, &data, &datalen, src, srclen, 0, 0);
+
+ src += len;
+ srclen -= len;
+ /* The parser might return something it cannot decode, so it skips
+ * the block returning no data
+ */
+ if (data == NULL || datalen == 0)
+ continue;
+ ret = avcodec_decode_video(v->dec_ctx, v->d_frame, &full_frame, data, datalen);
+ if (full_frame == 1) /* full frame */
+ break;
+ if (ret < 0) {
+ ast_log(LOG_NOTICE, "Error decoding\n");
+ break;
+ }
+ }
+ if (srclen != 0) /* update b with leftover data */
+ bcopy(src, b->data, srclen);
+ b->used = srclen;
+ b->ebit = 0;
+ return full_frame;
+}
+
+static struct video_codec_desc h263p_codec = {
+ .name = "h263p",
+ .format = AST_FORMAT_H263_PLUS,
+ .enc_init = h263p_enc_init,
+ .enc_encap = h263p_encap,
+ .enc_run = ffmpeg_encode,
+ .dec_init = NULL,
+ .dec_decap = h263p_decap,
+ .dec_run = ffmpeg_decode
+};
+
+/*--- Plain h263 support --------*/
+
+static int h263_enc_init(AVCodecContext *enc_ctx)
+{
+ /* XXX check whether these are supported */
+ enc_ctx->flags |= CODEC_FLAG_H263P_UMV;
+ enc_ctx->flags |= CODEC_FLAG_H263P_AIC;
+ enc_ctx->flags |= CODEC_FLAG_H263P_SLICE_STRUCT;
+ enc_ctx->flags |= CODEC_FLAG_AC_PRED;
+
+ return 0;
+}
+
+/*
+ * h263 encapsulation is specified in RFC2190. There are three modes
+ * defined (A, B, C), with 4, 8 and 12 bytes of header, respectively.
+ * The header is made as follows
+ * 0.....................|.......................|.............|....31
+ * F:1 P:1 SBIT:3 EBIT:3 SRC:3 I:1 U:1 S:1 A:1 R:4 DBQ:2 TRB:3 TR:8
+ * FP = 0- mode A, (only one word of header)
+ * FP = 10 mode B, and also means this is an I or P frame
+ * FP = 11 mode C, and also means this is a PB frame.
+ * SBIT, EBIT nuber of bits to ignore at beginning (msbits) and end (lsbits)
+ * SRC bits 6,7,8 from the h263 PTYPE field
+ * I = 0 intra-coded, 1 = inter-coded (bit 9 from PTYPE)
+ * U = 1 for Unrestricted Motion Vector (bit 10 from PTYPE)
+ * S = 1 for Syntax Based Arith coding (bit 11 from PTYPE)
+ * A = 1 for Advanced Prediction (bit 12 from PTYPE)
+ * R = reserved, must be 0
+ * DBQ = differential quantization, DBQUANT from h263, 0 unless we are using
+ * PB frames
+ * TRB = temporal reference for bframes, also 0 unless this is a PB frame
+ * TR = temporal reference for P frames, also 0 unless PB frame.
+ *
+ * Mode B and mode C description omitted.
+ *
+ * An RTP frame can start with a PSC 0000 0000 0000 0000 1000 0
+ * or with a GBSC, which also has the first 17 bits as a PSC.
+ * Note - PSC are byte-aligned, GOB not necessarily. PSC start with
+ * PSC:22 0000 0000 0000 0000 1000 00 picture start code
+ * TR:8 .... .... temporal reference
+ * PTYPE:13 or more ptype...
+ * If we don't fragment a GOB SBIT and EBIT = 0.
+ * reference, 8 bit)
+ *
+ * The assumption below is that we start with a PSC.
+ */
+static struct ast_frame *h263_encap(struct fbuf_t *b, int mtu,
+ struct ast_frame **tail)
+{
+ uint8_t *d = b->data;
+ int start = 0, i, len = b->used;
+ struct ast_frame *f, *cur = NULL, *first = NULL;
+ const int pheader_len = 4; /* Use RFC-2190 Mode A */
+ uint8_t h263_hdr[12]; /* worst case, room for a type c header */
+ uint8_t *h = h263_hdr; /* shorthand */
+
+#define H263_MIN_LEN 6
+ if (len < H263_MIN_LEN) /* unreasonably small */
+ return NULL;
+
+ bzero(h263_hdr, sizeof(h263_hdr));
+ /* Now set the header bytes. Only type A by now,
+ * and h[0] = h[2] = h[3] = 0 by default.
+ * PTYPE starts 30 bits in the picture, so the first useful
+ * bit for us is bit 36 i.e. within d[4] (0 is the msbit).
+ * SRC = d[4] & 0x1c goes into data[1] & 0xe0
+ * I = d[4] & 0x02 goes into data[1] & 0x10
+ * U = d[4] & 0x01 goes into data[1] & 0x08
+ * S = d[5] & 0x80 goes into data[1] & 0x04
+ * A = d[5] & 0x40 goes into data[1] & 0x02
+ * R = 0 goes into data[1] & 0x01
+ * Optimizing it, we have
+ */
+ h[1] = ( (d[4] & 0x1f) << 3 ) | /* SRC, I, U */
+ ( (d[5] & 0xc0) >> 5 ); /* S, A, R */
+
+ /* now look for the next PSC or GOB header. First try to hit
+ * a '0' byte then look around for the 0000 0000 0000 0000 1 pattern
+ * which is both in the PSC and the GBSC.
+ */
+ for (i = H263_MIN_LEN, start = 0; start < len; start = i, i += 3) {
+ //ast_log(LOG_WARNING, "search at %d of %d/%d\n", i, start, len);
+ for (; i < len ; i++) {
+ uint8_t x, rpos, lpos;
+ int rpos_i; /* index corresponding to rpos */
+ if (d[i] != 0) /* cannot be in a GBSC */
+ continue;
+ if (i > len - 1)
+ break;
+ x = d[i+1];
+ if (x == 0) /* next is equally good */
+ continue;
+ /* see if around us we can make 16 '0' bits for the GBSC.
+ * Look for the first bit set on the right, and then
+ * see if we have enough 0 on the left.
+ * We are guaranteed to end before rpos == 0
+ */
+ for (rpos = 0x80, rpos_i = 8; rpos; rpos >>= 1, rpos_i--)
+ if (x & rpos) /* found the '1' bit in GBSC */
+ break;
+ x = d[i-1]; /* now look behind */
+ for (lpos = rpos; lpos ; lpos >>= 1)
+ if (x & lpos) /* too early, not a GBSC */
+ break;
+ if (lpos) /* as i said... */
+ continue;
+ /* now we have a GBSC starting somewhere in d[i-1],
+ * but it might be not byte-aligned
+ */
+ if (rpos == 0x80) { /* lucky case */
+ i = i - 1;
+ } else { /* XXX to be completed */
+ ast_log(LOG_WARNING, "unaligned GBSC 0x%x %d\n",
+ rpos, rpos_i);
+ }
+ break;
+ }
+ /* This frame is up to offset i (not inclusive).
+ * We do not split it yet even if larger than MTU.
+ */
+ f = create_video_frame(d + start, d+i, AST_FORMAT_H263,
+ pheader_len, cur);
+
+ if (!f)
+ break;
+ bcopy(h, f->data, 4); /* copy the h263 header */
+ /* XXX to do: if not aligned, fix sbit and ebit,
+ * then move i back by 1 for the next frame
+ */
+ if (!cur)
+ first = f;
+ cur = f;
+ }
+
+ if (cur)
+ cur->subclass |= 1; // RTP Marker
+
+ *tail = cur;
+ return first;
+}
+
+/* XXX We only drop the header here, but maybe we need more. */
+static int h263_decap(struct fbuf_t *b, uint8_t *data, int len)
+{
+ if (len < 4) {
+ ast_log(LOG_WARNING, "invalid framesize %d\n", len);
+ return 1; /* error */
+ }
+
+ if ( (data[0] & 0x80) == 0) {
+ len -= 4;
+ data += 4;
+ } else {
+ ast_log(LOG_WARNING, "unsupported mode 0x%x\n",
+ data[0]);
+ return 1;
+ }
+ return fbuf_append(b, data, len, 0, 0); /* XXX no bit alignment support yet */
+}
+
+static struct video_codec_desc h263_codec = {
+ .name = "h263",
+ .format = AST_FORMAT_H263,
+ .enc_init = h263_enc_init,
+ .enc_encap = h263_encap,
+ .enc_run = ffmpeg_encode,
+ .dec_init = NULL,
+ .dec_decap = h263_decap,
+ .dec_run = ffmpeg_decode
+
+};
+
+/*---- h261 support -----*/
+static int h261_enc_init(AVCodecContext *enc_ctx)
+{
+ /* It is important to set rtp_payload_size = 0, otherwise
+ * ffmpeg in h261 mode will produce output that it cannot parse.
+ * Also try to send I frames more frequently than with other codecs.
+ */
+ enc_ctx->rtp_payload_size = 0; /* important - ffmpeg fails otherwise */
+
+ return 0;
+}
+
+/*
+ * The encapsulation of H261 is defined in RFC4587 which obsoletes RFC2032
+ * The bitstream is preceded by a 32-bit header word:
+ * SBIT:3 EBIT:3 I:1 V:1 GOBN:4 MBAP:5 QUANT:5 HMVD:5 VMVD:5
+ * SBIT and EBIT are the bits to be ignored at beginning and end,
+ * I=1 if the stream has only INTRA frames - cannot change during the stream.
+ * V=0 if motion vector is not used. Cannot change.
+ * GOBN is the GOB number in effect at the start of packet, 0 if we
+ * start with a GOB header
+ * QUANT is the quantizer in effect, 0 if we start with GOB header
+ * HMVD reference horizontal motion vector. 10000 is forbidden
+ * VMVD reference vertical motion vector, as above.
+ * Packetization should occur at GOB boundaries, and if not possible
+ * with MacroBlock fragmentation. However it is likely that blocks
+ * are not bit-aligned so we must take care of this.
+ */
+static struct ast_frame *h261_encap(struct fbuf_t *b, int mtu,
+ struct ast_frame **tail)
+{
+ uint8_t *d = b->data;
+ int start = 0, i, len = b->used;
+ struct ast_frame *f, *cur = NULL, *first = NULL;
+ const int pheader_len = 4;
+ uint8_t h261_hdr[4];
+ uint8_t *h = h261_hdr; /* shorthand */
+ int sbit = 0, ebit = 0;
+
+#define H261_MIN_LEN 10
+ if (len < H261_MIN_LEN) /* unreasonably small */
+ return NULL;
+
+ bzero(h261_hdr, sizeof(h261_hdr));
+
+ /* Similar to the code in h263_encap, but the marker there is longer.
+ * Start a few bytes within the bitstream to avoid hitting the marker
+ * twice. Note we might access the buffer at len, but this is ok because
+ * the caller has it oversized.
+ */
+ for (i = H261_MIN_LEN, start = 0; start < len - 1; start = i, i += 4) {
+#if 0 /* test - disable packetization */
+ i = len; /* wrong... */
+#else
+ int found = 0, found_ebit = 0; /* last GBSC position found */
+ for (; i < len ; i++) {
+ uint8_t x, rpos, lpos;
+ if (d[i] != 0) /* cannot be in a GBSC */
+ continue;
+ x = d[i+1];
+ if (x == 0) /* next is equally good */
+ continue;
+ /* See if around us we find 15 '0' bits for the GBSC.
+ * Look for the first bit set on the right, and then
+ * see if we have enough 0 on the left.
+ * We are guaranteed to end before rpos == 0
+ */
+ for (rpos = 0x80, ebit = 7; rpos; ebit--, rpos >>= 1)
+ if (x & rpos) /* found the '1' bit in GBSC */
+ break;
+ x = d[i-1]; /* now look behind */
+ for (lpos = (rpos >> 1); lpos ; lpos >>= 1)
+ if (x & lpos) /* too early, not a GBSC */
+ break;
+ if (lpos) /* as i said... */
+ continue;
+ /* now we have a GBSC starting somewhere in d[i-1],
+ * but it might be not byte-aligned. Just remember it.
+ */
+ if (i - start > mtu) /* too large, stop now */
+ break;
+ found_ebit = ebit;
+ found = i;
+ i += 4; /* continue forward */
+ }
+ if (i >= len) { /* trim if we went too forward */
+ i = len;
+ ebit = 0; /* hopefully... should ask the bitstream ? */
+ }
+ if (i - start > mtu && found) {
+ /* use the previous GBSC, hope is within the mtu */
+ i = found;
+ ebit = found_ebit;
+ }
+#endif /* test */
+ if (i - start < 4) /* XXX too short ? */
+ continue;
+ /* This frame is up to offset i (not inclusive).
+ * We do not split it yet even if larger than MTU.
+ */
+ f = create_video_frame(d + start, d+i, AST_FORMAT_H261,
+ pheader_len, cur);
+
+ if (!f)
+ break;
+ /* recompute header with I=0, V=1 */
+ h[0] = ( (sbit & 7) << 5 ) | ( (ebit & 7) << 2 ) | 1;
+ bcopy(h, f->data, 4); /* copy the h261 header */
+ if (ebit) /* not aligned, restart from previous byte */
+ i--;
+ sbit = (8 - ebit) & 7;
+ ebit = 0;
+ if (!cur)
+ first = f;
+ cur = f;
+ }
+ if (cur)
+ cur->subclass |= 1; // RTP Marker
+
+ *tail = cur;
+ return first;
+}
+
+/*
+ * Pieces might be unaligned so we really need to put them together.
+ */
+static int h261_decap(struct fbuf_t *b, uint8_t *data, int len)
+{
+ int ebit, sbit;
+
+ if (len < 8) {
+ ast_log(LOG_WARNING, "invalid framesize %d\n", len);
+ return 1;
+ }
+ sbit = (data[0] >> 5) & 7;
+ ebit = (data[0] >> 2) & 7;
+ len -= 4;
+ data += 4;
+ return fbuf_append(b, data, len, sbit, ebit);
+}
+
+static struct video_codec_desc h261_codec = {
+ .name = "h261",
+ .format = AST_FORMAT_H261,
+ .enc_init = h261_enc_init,
+ .enc_encap = h261_encap,
+ .enc_run = ffmpeg_encode,
+ .dec_init = NULL,
+ .dec_decap = h261_decap,
+ .dec_run = ffmpeg_decode
+};
+
+/* mpeg4 support */
+static int mpeg4_enc_init(AVCodecContext *enc_ctx)
+{
+#if 0
+ //enc_ctx->flags |= CODEC_FLAG_LOW_DELAY; /*don't use b frames ?*/
+ enc_ctx->flags |= CODEC_FLAG_AC_PRED;
+ enc_ctx->flags |= CODEC_FLAG_H263P_UMV;
+ enc_ctx->flags |= CODEC_FLAG_QPEL;
+ enc_ctx->flags |= CODEC_FLAG_4MV;
+ enc_ctx->flags |= CODEC_FLAG_GMC;
+ enc_ctx->flags |= CODEC_FLAG_LOOP_FILTER;
+ enc_ctx->flags |= CODEC_FLAG_H263P_SLICE_STRUCT;
+#endif
+ enc_ctx->rtp_payload_size = 0; /* important - ffmpeg fails otherwise */
+ return 0;
+}
+
+/* simplistic encapsulation - just split frames in mtu-size units */
+static struct ast_frame *mpeg4_encap(struct fbuf_t *b, int mtu,
+ struct ast_frame **tail)
+{
+ struct ast_frame *f, *cur = NULL, *first = NULL;
+ uint8_t *d = b->data;
+ uint8_t *end = d + b->used;
+ int len;
+
+ for (;d < end; d += len, cur = f) {
+ len = MIN(mtu, end - d);
+ f = create_video_frame(d, d + len, AST_FORMAT_MP4_VIDEO, 0, cur);
+ if (!f)
+ break;
+ if (!first)
+ first = f;
+ }
+ if (cur)
+ cur->subclass |= 1;
+ *tail = cur;
+ return first;
+}
+
+static int mpeg4_decap(struct fbuf_t *b, uint8_t *data, int len)
+{
+ return fbuf_append(b, data, len, 0, 0);
+}
+
+static int mpeg4_decode(struct video_dec_desc *v, struct fbuf_t *b)
+{
+ int full_frame = 0, datalen = b->used;
+ int ret = avcodec_decode_video(v->dec_ctx, v->d_frame, &full_frame,
+ b->data, datalen);
+ if (ret < 0) {
+ ast_log(LOG_NOTICE, "Error decoding\n");
+ ret = datalen; /* assume we used everything. */
+ }
+ datalen -= ret;
+ if (datalen > 0) /* update b with leftover bytes */
+ bcopy(b->data + ret, b->data, datalen);
+ b->used = datalen;
+ b->ebit = 0;
+ return full_frame;
+}
+
+static struct video_codec_desc mpeg4_codec = {
+ .name = "mpeg4",
+ .format = AST_FORMAT_MP4_VIDEO,
+ .enc_init = mpeg4_enc_init,
+ .enc_encap = mpeg4_encap,
+ .enc_run = ffmpeg_encode,
+ .dec_init = NULL,
+ .dec_decap = mpeg4_decap,
+ .dec_run = mpeg4_decode
+};
+
+static int h264_enc_init(AVCodecContext *enc_ctx)
+{
+ enc_ctx->flags |= CODEC_FLAG_TRUNCATED;
+ //enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
+ //enc_ctx->flags2 |= CODEC_FLAG2_FASTPSKIP;
+ /* TODO: Maybe we need to add some other flags */
+ enc_ctx->rtp_mode = 0;
+ enc_ctx->rtp_payload_size = 0;
+ enc_ctx->bit_rate_tolerance = enc_ctx->bit_rate;
+ return 0;
+}
+
+static int h264_dec_init(AVCodecContext *dec_ctx)
+{
+ dec_ctx->flags |= CODEC_FLAG_TRUNCATED;
+
+ return 0;
+}
+
+/*
+ * The structure of a generic H.264 stream is:
+ * - 0..n 0-byte(s), unused, optional. one zero-byte is always present
+ * in the first NAL before the start code prefix.
+ * - start code prefix (3 bytes): 0x000001
+ * (the first bytestream has a
+ * like these 0x00000001!)
+ * - NAL header byte ( F[1] | NRI[2] | Type[5] ) where type != 0
+ * - byte-stream
+ * - 0..n 0-byte(s) (padding, unused).
+ * Segmentation in RTP only needs to be done on start code prefixes.
+ * If fragments are too long... we don't support it yet.
+ * - encapsulate (or fragment) the byte-stream (with NAL header included)
+ */
+static struct ast_frame *h264_encap(struct fbuf_t *b, int mtu,
+ struct ast_frame **tail)
+{
+ struct ast_frame *f = NULL, *cur = NULL, *first = NULL;
+ uint8_t *d, *start = b->data;
+ uint8_t *end = start + b->used;
+
+ /* Search the first start code prefix - ITU-T H.264 sec. B.2,
+ * and move start right after that, on the NAL header byte.
+ */
+#define HAVE_NAL(x) (x[-4] == 0 && x[-3] == 0 && x[-2] == 0 && x[-1] == 1)
+ for (start += 4; start < end; start++) {
+ int ty = start[0] & 0x1f;
+ if (HAVE_NAL(start) && ty != 0 && ty != 31)
+ break;
+ }
+ /* if not found, or too short, we just skip the next loop and are done. */
+
+ /* Here follows the main loop to create frames. Search subsequent start
+ * codes, and then possibly fragment the unit into smaller fragments.
+ */
+ for (;start < end - 4; start = d) {
+ int size; /* size of current block */
+ uint8_t hdr[2]; /* add-on header when fragmenting */
+ int ty = 0;
+
+ /* now search next nal */
+ for (d = start + 4; d < end; d++) {
+ ty = d[0] & 0x1f;
+ if (HAVE_NAL(d))
+ break; /* found NAL */
+ }
+ /* have a block to send. d past the start code unless we overflow */
+ if (d >= end) { /* NAL not found */
+ d = end + 4;
+ } else if (ty == 0 || ty == 31) { /* found but invalid type, skip */
+ ast_log(LOG_WARNING, "skip invalid nal type %d at %d of %d\n",
+ ty, d - (uint8_t *)b->data, b->used);
+ continue;
+ }
+
+ size = d - start - 4; /* don't count the end */
+
+ if (size < mtu) { // test - don't fragment
+ // Single NAL Unit
+ f = create_video_frame(start, d - 4, AST_FORMAT_H264, 0, cur);
+ if (!f)
+ break;
+ if (!first)
+ first = f;
+
+ cur = f;
+ continue;
+ }
+
+ // Fragmented Unit (Mode A: no DON, very weak)
+ hdr[0] = (*start & 0xe0) | 28; /* mark as a fragmentation unit */
+ hdr[1] = (*start++ & 0x1f) | 0x80 ; /* keep type and set START bit */
+ size--; /* skip the NAL header */
+ while (size) {
+ uint8_t *data;
+ int frag_size = MIN(size, mtu);
+
+ f = create_video_frame(start, start+frag_size, AST_FORMAT_H264, 2, cur);
+ if (!f)
+ break;
+ size -= frag_size; /* skip this data block */
+ start += frag_size;
+
+ data = f->data;
+ data[0] = hdr[0];
+ data[1] = hdr[1] | (size == 0 ? 0x40 : 0); /* end bit if we are done */
+ hdr[1] &= ~0x80; /* clear start bit for subsequent frames */
+ if (!first)
+ first = f;
+ cur = f;
+ }
+ }
+
+ if (cur)
+ cur->subclass |= 1; // RTP Marker
+
+ *tail = cur;
+
+ return first;
+}
+
+static int h264_decap(struct fbuf_t *b, uint8_t *data, int len)
+{
+ /* Start Code Prefix (Annex B in specification) */
+ uint8_t scp[] = { 0x00, 0x00, 0x00, 0x01 };
+ int retval = 0;
+ int type, ofs = 0;
+
+ if (len < 2) {
+ ast_log(LOG_WARNING, "--- invalid len %d\n", len);
+ return 1;
+ }
+ /* first of all, check if the packet has F == 0 */
+ if (data[0] & 0x80) {
+ ast_log(LOG_WARNING, "--- forbidden packet; nal: %02x\n",
+ data[0]);
+ return 1;
+ }
+
+ type = data[0] & 0x1f;
+ switch (type) {
+ case 0:
+ case 31:
+ ast_log(LOG_WARNING, "--- invalid type: %d\n", type);
+ return 1;
+ case 24:
+ case 25:
+ case 26:
+ case 27:
+ case 29:
+ ast_log(LOG_WARNING, "--- encapsulation not supported : %d\n", type);
+ return 1;
+ case 28: /* FU-A Unit */
+ if (data[1] & 0x80) { // S == 1, import F and NRI from next
+ data[1] &= 0x1f; /* preserve type */
+ data[1] |= (data[0] & 0xe0); /* import F & NRI */
+ retval = fbuf_append(b, scp, sizeof(scp), 0, 0);
+ ofs = 1;
+ } else {
+ ofs = 2;
+ }
+ break;
+ default: /* From 1 to 23 (Single NAL Unit) */
+ retval = fbuf_append(b, scp, sizeof(scp), 0, 0);
+ }
+ if (!retval)
+ retval = fbuf_append(b, data + ofs, len - ofs, 0, 0);
+ if (retval)
+ ast_log(LOG_WARNING, "result %d\n", retval);
+ return retval;
+}
+
+static struct video_codec_desc h264_codec = {
+ .name = "h264",
+ .format = AST_FORMAT_H264,
+ .enc_init = h264_enc_init,
+ .enc_encap = h264_encap,
+ .enc_run = ffmpeg_encode,
+ .dec_init = h264_dec_init,
+ .dec_decap = h264_decap,
+ .dec_run = ffmpeg_decode
+};
+
+/*
+ * Table of translation between asterisk and ffmpeg formats.
+ * We need also a field for read and write (encoding and decoding), because
+ * e.g. H263+ uses different codec IDs in ffmpeg when encoding or decoding.
+ */
+struct _cm { /* map ffmpeg codec types to asterisk formats */
+ uint32_t ast_format; /* 0 is a terminator */
+ enum CodecID codec;
+ enum { CM_RD = 1, CM_WR = 2, CM_RDWR = 3 } rw; /* read or write or both ? */
+ //struct video_codec_desc *codec_desc;
+};
+
+static struct _cm video_formats[] = {
+ { AST_FORMAT_H263_PLUS, CODEC_ID_H263, CM_RD }, /* incoming H263P ? */
+ { AST_FORMAT_H263_PLUS, CODEC_ID_H263P, CM_WR },
+ { AST_FORMAT_H263, CODEC_ID_H263, CM_RD },
+ { AST_FORMAT_H263, CODEC_ID_H263, CM_WR },
+ { AST_FORMAT_H261, CODEC_ID_H261, CM_RDWR },
+ { AST_FORMAT_H264, CODEC_ID_H264, CM_RDWR },
+ { AST_FORMAT_MP4_VIDEO, CODEC_ID_MPEG4, CM_RDWR },
+ { 0, 0, 0 },
+};
+
+
+/*! \brief map an asterisk format into an ffmpeg one */
+static enum CodecID map_video_format(uint32_t ast_format, int rw)
+{
+ struct _cm *i;
+
+ for (i = video_formats; i->ast_format != 0; i++)
+ if (ast_format & i->ast_format && rw & i->rw && rw & i->rw)
+ return i->codec;
+ return CODEC_ID_NONE;
+}
+
+/* pointers to supported codecs. We assume the first one to be non null. */
+static struct video_codec_desc *supported_codecs[] = {
+ &h263p_codec,
+ &h264_codec,
+ &h263_codec,
+ &h261_codec,
+ &mpeg4_codec,
+ NULL
+};
+
+/*
+ * Map the AST_FORMAT to the library. If not recognised, fail.
+ * This is useful in the input path where we get frames.
+ */
+static struct video_codec_desc *map_video_codec(int fmt)
+{
+ int i;
+
+ for (i = 0; supported_codecs[i]; i++)
+ if (fmt == supported_codecs[i]->format) {
+ ast_log(LOG_WARNING, "using %s for format 0x%x\n",
+ supported_codecs[i]->name, fmt);
+ return supported_codecs[i];
+ }
+ return NULL;
+}
+
+/*! \brief uninitialize the descriptor for remote video stream */
+static struct video_dec_desc *dec_uninit(struct video_dec_desc *v)
+{
+ int i;
+
+ if (v == NULL) /* not initialized yet */
+ return NULL;
+ if (v->parser) {
+ av_parser_close(v->parser);
+ v->parser = NULL;
+ }
+ if (v->dec_ctx) {
+ avcodec_close(v->dec_ctx);
+ av_free(v->dec_ctx);
+ v->dec_ctx = NULL;
+ }
+ if (v->d_frame) {
+ av_free(v->d_frame);
+ v->d_frame = NULL;
+ }
+ v->codec = NULL; /* only a reference */
+ v->d_callbacks = NULL; /* forget the decoder */
+ v->discard = 1; /* start in discard mode */
+ for (i = 0; i < N_DEC_IN; i++)
+ fbuf_free(&v->dec_in[i]);
+ fbuf_free(&v->dec_out);
+ ast_free(v);
+ return NULL; /* error, in case someone cares */
+}
+
+/*
+ * initialize ffmpeg resources used for decoding frames from the network.
+ */
+static struct video_dec_desc *dec_init(uint32_t the_ast_format)
+{
+ enum CodecID codec;
+ struct video_dec_desc *v = ast_calloc(1, sizeof(*v));
+ if (v == NULL)
+ return NULL;
+
+ v->discard = 1;
+
+ v->d_callbacks = map_video_codec(the_ast_format);
+ if (v->d_callbacks == NULL) {
+ ast_log(LOG_WARNING, "cannot find video codec, drop input 0x%x\n", the_ast_format);
+ return dec_uninit(v);
+ }
+
+ codec = map_video_format(v->d_callbacks->format, CM_RD);
+
+ v->codec = avcodec_find_decoder(codec);
+ if (!v->codec) {
+ ast_log(LOG_WARNING, "Unable to find the decoder for format %d\n", codec);
+ return dec_uninit(v);
+ }
+ /*
+ * Initialize the codec context.
+ */
+ v->dec_ctx = avcodec_alloc_context();
+ if (!v->dec_ctx) {
+ ast_log(LOG_WARNING, "Cannot allocate the decoder context\n");
+ return dec_uninit(v);
+ }
+ /* XXX call dec_init() ? */
+ if (avcodec_open(v->dec_ctx, v->codec) < 0) {
+ ast_log(LOG_WARNING, "Cannot open the decoder context\n");
+ av_free(v->dec_ctx);
+ v->dec_ctx = NULL;
+ return dec_uninit(v);
+ }
+
+ v->parser = av_parser_init(codec);
+ if (!v->parser) {
+ ast_log(LOG_WARNING, "Cannot initialize the decoder parser\n");
+ return dec_uninit(v);
+ }
+
+ v->d_frame = avcodec_alloc_frame();
+ if (!v->d_frame) {
+ ast_log(LOG_WARNING, "Cannot allocate decoding video frame\n");
+ return dec_uninit(v);
+ }
+ v->dec_in_cur = &v->dec_in[0]; /* buffer for incoming frames */
+ v->dec_in_dpy = NULL; /* nothing to display */
+
+ return v; /* ok */
+}
+/*------ end codec specific code -----*/